Through the years a number of amusement devices have been created which include one or more self-propelled miniature vehicles together with control systems for remotely operating the vehicles. A wide variety of control systems have been utilized for vehicle control and have included systems utilizing electrical controllers coupled to electrodes fabricated within the system track, radio frequency transmitting and receiving systems, infrared transmitting and receiving systems, and visible light communicating systems.
Of the various systems implemented, visible light control systems have several advantages in that the visible light energy is easy and inexpensive to produce and is easy for operators to accurately direct toward the to-be-controlled vehicles. In addition, since visible light includes a plurality of distinct colors, the use of visible light control systems permits the implementation of multiple control functions which are color selective.
These advantages have led practitioners in the art to develop several light responsive systems. One such system is set forth in U.S. Pat. No. 4,201,012 issued to Marshall for a REMOTE CONTROL VEHICLE in which a vehicle supports four light dependent resistors on its upper surface and includes a drive motor for driving the vehicle in forward or reverse direction and a steering motor for turning the vehicle in either left or right directions. The motors are coupled to the light dependent resistors such that illumination of a selected light dependent resistor produces a unique operation of either the steering or drive motors. Each of the light dependent resistors may be coupled to a light color sensitive filter to provide color selective response.
U.S. Pat. No. 4,086,724 issued to McCaslin sets forth a MOTORIZED TOY VEHICLE HAVING IMPROVED CONTROL MEANS in which a toy vehicle is propelled by a drive motor and is directed by a steering motor. A control system operates to permit the vehicle to change direction, move forwardly or to stop, in response to an external command such as sound energy or light energy. The control system is operative to steer the vehicle in response to the duration of applied control energy.
U.S. Pat. No. 3,406,481 issued to Tachi sets forth a MOVING TOY DIRECTION-VARIABLE BY A MODULATING RAY in which a toy vehicle is propelled in either direction by a pair of driven motors which are controlled by a rotatable tower member. The tower member supports a pair of photoconductive cells which operate each of the motors individually in response to light received by the cell. The operation of the vehicle is controlled such that the vehicle seeks equal illumination of the two photoconductive cells and is configured to cause the vehicle to seek to follow the source of modulating light incident upon the cells.
U.S. Pat. No. 3,314,189 issued to Carroll sets forth a REMOTE LIGHT ACTUATED CONTROL MEANS FOR MODELS in which a toy vehicle is operated by a drive motor and a steering motor. Light sources of different wavelengths are provided to permit the simultaneous operation of multiple toy vehicles about the track. A plurality of power conductors are supported upon the track surface and provide electrical energy to power the toy vehicles through a plurality of downwardly extending brush contacts on each of the toy vehicles.
U.S. Pat. No. 3,849,931 issued to Gulley, Jr. sets forth a DIRECTION SEEKING TOY VEHICLE in which a battery power toy vehicle includes drive means rotatably secured to the vehicle body to provide turning and maneuvering of the vehicle. A pair of light cells are supported on the forward portion of the vehicle and are isolated from each other by an intervening rib surface. The light cells on each side of the vehicle individually operate the drive motors on the associated side of the vehicle. As a result, the vehicle tends to follow a light source directed at the front portion of the vehicle.
British Pat. No. 848,454 issued to Nothelfer sets forth a REMOTE CONTROL SYSTEM FOR TOYS which operates in response to sound energy or light energy.
British Pat. No. 2,055,594 issued to Masudaya sets forth a SELF-POWERED TOY VEHICLE which responds to either sound or light energy control signals.
U.S. Pat. No. 3,308,577 issued to Holt sets forth a MINIATURE SAILING GAME CONTROLLED BY PHOTOCELLS in which a miniature sailboat includes a motor operated rudder coupled to a pair of light responsive photocells. The photocells are positioned on either side of the vessel and are operative to control the rudder movement in response to illumination of either of the photocells thereby achieving vessel steering.
In addition to the foregoing, various other amusement devices and toys have been provided. For example, U.S. Pat. No. 4,310,987 sets forth a rolling amusement device powered by light falling upon solar cells within the device. In addition, U.S. Pat. Nos. 4,702,718 and 4,662,854 set forth self-propelled toy devices which are responsive to light energy.
While the foregoing described prior art devices have enjoyed some limited success, they have generally been found to be impractical for commercial manufacture due to several limitations relating to receiver sensitivity and response to ambient light. It has been found that interference of ambient light in light responsive vehicles is particularly troublesome due to the wide range of ambient light conditions under which such vehicles are required to operate. Generally speaking, the ambient light conditions in typical toy vehicle use may vary from dark or semi-dark to bright sunlight and various artificial light conditions in between. As a result, there arises a need in the art for a light responsive remote control vehicle which successfully operates over a wide range of ambient light conditions and which is sufficiently inexpensive, small and efficient to be used in miniaturized toy vehicles.